Spirooxindole and spirodehydroindole alkaloids and process therefor



United States Patent 3 219,661 SPIROOXINDOLE ANi) SPIRODEHYDROINDOLEALKALOIDS AND PROCESS THEREFOR John Shavel, Jr., Mendham, and HaroldZinnes, Rockaway, N.J., assignors to Warner-Lambert PharmaceuticalCompany, Morris Plains, N.J., a corporation of Delaware N0 Drawing.Filed Dec. 14, 1962, Ser. No. 244,557 23 Claims. (Cl. 260240) Thisinvention relates to novel spirooxindole alkaloids of the formula:

and

wherein R represents hydrogen,

or lower alkyl such as methyl; R represents hydrogen, keto, hydroxy,lower alkoxy such as methoxy or acyloxy such as acetoxy; R representshydrogen, or =CHC H R in which R represents hydrogen or halogen such aschlorine or bromine, hydroXy or lower alkoxy such as methoxy and Rrepresents hydrogen or wherein R R R and R have the same meaning asdescribed above. Thus, for example, l6-methyl-17- Since the carbon atomat position -3 is asymmetric, two epimers are possible, that is,spiroxyane and epispiroxyane, and these epirners are also Within thescope of this invention. The epimers are readily diilerentiated on paperchromatography by their mobility; the 3- epimer has the greatermobility. Thus, for example, l7-hydroxy- 18-benzylidene-3 epispiroxyanehas an R of 0.60 relative to 17 hydroxy 18 benzylidenespir-oxyane whichhas an Rf of 0.36. In addition, the 3-epi compounds give a positivemercuric acetate test which comprises heating a solution of mg. of thecompound to -be tested at 45 C. in 2 m1. 5% acetic acid and 200 mg.mercuric acetate. Within a few minutes crystalline mercurous acetate isprecipitated.

Exemplary of the new and novel spiroxyanes are spiroxyane,3-epispiroxyane, 16ix-methyl-l7a-hydroxyspiroxyane,16a-methyl-17a-hydroXy-3-epispiroxyane,16a-carbomethoxy-l7ot-hydroxyspiroxyane,

1 6a-carbomethoxy17a-hydroxy-3-epispiroxyane,1S-benzylidene-l7-hydroxyspiroxyane,18-benzylidene-17-hydroxy-3-epispiroxyane,17-acetoXy-1-aeetyl-16-carbomethoxyspiroxyane,17-acetoxy-l-acetyl-lfi-carbomethoxy-3-epispiroxyane, 17-ketospiroxyane,

17-ketoepispir0xyane, 16ix-methyl-l7-hydroxy-2-desoxyspiroxyane,16u-methyl-17-hydroxy-2-desoxy-3-epispiroxyane,16-carbomethoxy-17a-hydroxy-Z-desoxyspiroxyane, 16-carbomethcxy-17a-hydroXy-Z-desoxy-3-epispiroxyane, l8-benZylidene-l7fi-spiroxyane,

1 8-benzylidene- 17 B-B-epispi roxyane,

' I-S-benzylidene-l7-hydroxyspiroxyane,

18-benzylidenel7-hydroXy-3-epispiroxyane,17ot-acetoxy16u-carbomethoxysph'oxyane,l7rx-acetoxy-16u-carbomethoxy-3-epispiroxyane and the like.

The new and novel compounds of this invention have interesting andsignificant pharmacological activity and are particularly useful asanti-inflammatory, analgesic and cardiovascular agents. In addition,they are useful as intermediates for the production of other noveloxindoles.

- It is known in the art that when yohirnbane alkaloids are oxidized byt-butyl hypochlorite, and then treated with an alcoholic solution ofhydrogen chloride, 3-dehydroyohimbane chlorides are obtained. Thereaction may be represented by the following equation:

We have found that when yohimbane alkaloids are oxidized by t-butylhypochlorite and then hydrolyzed at a slightly acidic pH novel spiroxyanes are produced, Thus, for example, a methylene chloride-carbontetrachloride solution of yohimbine of the formula:

is oxidized by t-butyl hypochlorite and after the removal of the solventthe corresponding chloro derivative of the formula:

O CHaO-(l I OH is obtained. The chloro derivative is then hydrolyzed byrefluxing in 50% aqueous methanol having a pH of 6, to obtain aspiroxyane of the formula:

to its corresponding oxindole analog mitraphylline of the formula:

CH H l 3 CHaO- by first treating ajmalicine with t-butyl hypochloriteand then hydrolyzing as described above. The spiroxyanes obtained by thenovel oxidative process of this invention may be treated further toyield novel derivatives. Thus, for example, when16-carbomethoxy-17-hydroxyspiroxyane is used as the starting materialthe following derivatives as exemplified by the following series ofreactions are readily obtained.

=0 Reaction 0 A O=C H A020 ofia C3304) Heat 95 O. CH3

=0 Reaction N 2 CH3O& 2227 C. I

O(|%-CH3 Reation O Cyclo- H hexauone Aluminum H phenoxlde aild xy eneReflux Reaction D g LiAlH 11 Refluxing H2O dioxane I Reaction A in theabove diagram involves acetylation of the spiroxyane with aceticanhydride at 9095 C. whereby l7-acetoxy-l-acetyl-l6-carbomethoxyspiroxyane is readily obtained. On the other hand, when the aceticanhydride reaction is allowed to proceed at 2227 C. as represented inReaction B, 17-acetoxy-l6-carbomethoxy spiroxyane is obtained. Thiscompound differs from the reaction product of A in the absence of theCOCH group on the nitrogen atom. Reaction C involves refluxing thespiroxyane in xylene with cyclohexanone and aluminum phenoxide to obtain17-keto spiroxyane. The latter whenreacted with an alkali metalborohydride such as potassium borohydride is readily converted into17-hydroxyspiroxyane. The l7-keto spiroxyane obtained when treated withbenzaldehyde in the presence of an alkali is readily converted into18-benzylidene-17-keto spiroxyane of the formula:

The benzylidene derivative is reactive with potassium borohydride toproduce 1S-benzylidene-l7-hydroxyspiroxyane. Reaction D represents thereduction of the spiroxyane With lithium aluminum hydride and thisreduction produces the 2-desoxy derivative that is l7hydroxy 16hydroxymethyl 2 desoxyspiroxyane. Employing analogous reactionconditions spiroxyanes such as, for example,l6-methyl-l7-hydroxyspiroxyane can be reduced also to their desoxyderivative by lithium aluminum hydride.

As can be readily appreciated, the starting materials described toprepare the novel compounds of this invention are alkaloids of theyohirnbane series and, depending upon the configuration of the carbonatom at the 3- position and the existence of cis or trans fusion of theD and E rings, different configurations are possible, that is,yohirnbane, 3-epiyohirnbane, alloyohimbane and 3- epialloyohimbane.Since the novel spiroxyanes are prepared from the yohirnbane alkaloids,the present invention also includes within its scope derivatives ofthese four families of spiroxyanes bearing R R and R substituents at the16, 17 and 18 positions, respectively.

The compounds of this invention may be converted to the pharmaceuticallyacceptable nontoxic acid addition or quarternary ammonium salts. Usefulacid addition salts are those from such acids as maleic, fumaric,benzoic, succinic, citric, tartaric, hydrochloric, hydrobromic,phosphoric and the like. The addition salts may be prepared in theconventional manner, for example, by treating a solution or suspensionof the free base in an inert organic solvent with the desired acid andthen recovering the salt which forms by crystallization techniques. Thequarternary salts are prepared by heating a solution of the base in asuitable solvent with a reactive alkyl halide such as methyl iodide,ethyl bromide, benzyl chloride or another reactive ester such as methylsulfate, ethyl sulfate and methyl p-toluene sulfonate.

For therapeutic uses the new and novel compounds of this inventioneither as the free base or in the form of a pharmaceutical acceptablenontoxic acid addition or quaternary ammonium salt may be formulatedwith a conventional pharmaceutical carrier to form tablets, capsules,elixirs, solutions, suspensions, suppositories and the like.

The following examples are included in order further to illustrate thepresent invention.

EXAMPLE 1 17acarb0methoxy-17a-lzydr0xyspir0xyane and 1611-6617-bomethoay-l 7a-hydroxy-S-epispiroxymze To a suspension (protected fromlight) of 8.85 g. (0.025 mole) yohimbine in 150 ml. methylene chloridecontaining 4 ml. triethylamine is added dropwise with stirring at +30 C.a solution of 9 ml. tert-butyl hypochlon'te in 25 ml. of carbontetrachloride, the addition requiring about minutes time for completion.After stirring an additional 15 minutes, the mixture is stirred with ml.of water. The layers are separated, the organic layer is washed with twomore 25 ml. portions of Water, and the organic layer is dried overanhydrous sodium sulfate. It is distilled in vacuo to dryness. Theresidue is dissolved in ml. methanol, and 60 ml. of water is added. ThepH of the solution is adjusted to 6.0 by the addition of 0.5 ml. glacialacetic acid and the solution is refluxed for 30 minutes. After removalof the methanol by distillation in vacuo, and the addition of 100 ml. ofwater, the pH is 4.4. The very small amount of gum which precipitates isfiltered ofr" and discarded, the clear orange filtrate is brought to apH 8.5 by the addition of aqueous ammonium hydroxide, and the mixture isextracted with chloroform. The chloroform solution is distilled in vacuoto yield a yellowish White amorphous solid. The solid is dissolved in 20ml. methanol and 5 ml. 6 N methanolic HCl is added slowly with stirringand cooling. Addition of 30 ml. anhydrous ether and scratching induceswhite crystals to form. After refrigeration at 46 C. for about 1 to 2hour-s there is collected 2.4 g. 16a-carbornethoxy17whydroxyspiroxyanehydrochloride hemihydrate, M.P. 230-234 C. decomposition, [011 +23(Water, c.':l.0). Recrystallization from methanol gives, M.P. 231-235 C.decomposition, +25 (water, c.:0.95), [111 +l30 (pyridine, c.:0.64), [M+16 ethanol, 6.21.0).

Calc.: C60.64, H-6.79, N--6.74, c1 s.53;

OCH37.44.

Found: C60.88, H6.98, N6.66, Cl8.60;

OCH3-7.08.

To a solution of 2 g. of the spiroxyane hydrochloride hemihydrate in 200ml. hot absolute ethanol is added 200 ml. dry benzene. The mixture isdistilled at atmospheric pressure to near dryness and the last traces ofsolvent are removed in vacuo. The residue is recrystallized twice frommethanol to give unhydrated 16mcarbomethoxy-l7cx-hydroxyspiroxyane, M.P.231 235 C. decomposition, +25 (Water, C.:0.65),[oc] +l37 (pyridine,c.:0.63), [111L +l7 (ethanol, c.:0.64); infrared:

11,13213350, 3210, 2800, 2760, 1725, 1702, 1610, 748 cmf Aggy.- 3460,3210, 2900, 2743, 172a, 1710, 1621 emf; ultraviolet: Xf Z'Q 251-252 (6=7220), 277-282 shoulder (e 1440) me A rrrin.: 227 (e=2590) m 1.

A11alysis.C H N O Calc.: C-68.08, H7.08, N7.56. Found: C68.02, H-7.21,N7.43.

The acidic ethereal methanol filtrate from the 160:-carbomethoxy-17a-hydroxyspiroxyane hydrochloride is distilled in vacuoto dryness, the residue is dissolved in ml. water, and 5 ml. 70%perchloric acid is added. The precipitate which forms is filtered 0d anddiscarded. The aqueous filtrate is basified with aqueous ammoniumhydroxide, and extracted with chloroform. Distillation in vacuo of thechloroform solution gives a residue which on trituration with petroleumether gives 3.5 g. of crude 16a carbomethovy 17cchydroxy-3-epispiroxyane. On chromatography it gives a single spot, Rf0.41 relative to 1606 carbomethoxy 17a hydroxy-S-epispiroxyane. On 0.16N. This substance gives a positive mercuric acetate test.

A slight excess of ethereal hydrogen chloride is added to a solution of2 g. of the amorphous solid in 150 ml. anhydrous ether while stirringand cooling on an ice bath. The gummy precipitate, thus obtained, istriturated with dry ether and then refluxed with 200 ml. methyl ethylketone. A small amount of insoluble material is filtered off and thefiltrate is concentrated by distillation at atmospheric pressure. Theinitial crops of reddish gummy material which separate out are filteredoff and the filtrate is concentrated further till white crystals beginto separate. After standing at room temperature for 16-24 hours thecrystals are collected and recrystallized from methyl ethyl ketone togive 550 mg. of pure 16a-carbomethoxy-17ahydroxy-3-epispiroxyanehydrochloride, M.P. 231235 C. decomposition, [a] +101 (water, c.=0.86);infrared:

11mg: 3380, 3130, 2600, 1727, 1622, 760; ultraviolet:

On paper chromatography it gives a single spot, Rf 0.38 relative to16oz-carbomethoxy-17a-hydroxyspiroxyane hydrochloride having Rf 0.14.The substance gives a positive mercuric acetate test.

Preparation of l6ot-carbomethoxy-l 7ot-hydr0xyspir0xyane using silvernitrate To a suspension (protected from light) of 8.85 g. (0.025 mole)yohimbine in 150 ml. methylene chloride containing 4 m1. triethylamineis added dropwise with stirring at 30 a solution of 9 ml. tert-butylhypochlorite in 25 ml. of carbon tetrachloride, the addition requiringabout minutes time for completion. After stirring an additional 15minutes, the mixture is stirred with 25 ml. water. The layers areseparated, the organic layer is washed with two more 25 ml. portions ofwater, and the organic layer is dried over anhydrous sodium sulfate. Itis distilled in vacuo to dryness, the residue is dissolved in amixtureof 50 ml. methanol and 25 ml. water on the addition of a solution of 3.6g. silver nitrate in a mixture of 50 ml. methanol and 10 ml. water asmall amount of white precipitate is formed. The mixture is refluxed forthirty minutes, during which time a considerable amount of silverchloride precipitated from solu tion. This is removed by filtration andthe filtrate is made alkaline with ammonium hydroxide. Extraction withchloroform, drying the chloroform solution over sodium sulfate anddistillation to dryness yields a yellowish white amorphous solid. Thisis dissolved in ml. methanol and 5 ml. 6N methanolic hydrogen chlorideis added slowly with stirring and cooling. Addition of 30 ml. anhydrousether and scratching induced white crystals to form. After refrigerationthere is obtained 1.8 g. 16a-carbomethoxy-17a-hydroxyspiroxyanehydrochloride, +25 (water, c.=1.0), identified by its infrared andultraviolet spectra.

EXAMPLE 2 16ot-methyl-17oi-hydroxyspiroxyane and 16a-methyl-17ahydroxy-3-epz'spiroxyane A mixture of 46.5 g. (0.15 mole)16a-methylyohimbol, 24 ml. triethylamine, and 900 ml. methylene chlorideis cooled to to and a solution of 27 ml. t-butyl hypochlorite in 81 ml.carbon tetrachloride is added dropwise with stirring over a period ofabout 15 minutes, the materials being protected from light. Afterstirring for an additional 15 minutes the reaction mixture is stirredwith 200 ml. water, the layers are separated and the organic layer isWashed with 300 ml. more water. The organic layer is dried over sodiumsulfate and distilled in vacuo to yield a dark oil which is dissolved in300 ml. methanol. After the addition of 300 ml. water followed by 1.5ml. glacial acetic acid to lower the pH to 6.0 the resulting solution isrefluxed 45 minutes. The methanol is distilled off and 400 ml. morewater is added. The small amount of dark insoluble material is filteredoff and discarded. The filtrate (pH 4.0) is made alkaline (pH 8.5) bythe addition of ammonium hydroxide and is then extracted withchloroform. The dried chloroform solution is distilled in vacuo todryness, and the residue is triturated with petroleum ether to yield anoff white amorphous powder. Paper chromatography shows two spots ofapproximately equal size having Rf .66 and .35, respectively. The solidis refluxed with 200 ml. acetone for 15 minutes and the mixture allowedto stand for 20 to 24 hours at 25 to 29 C. The resulting crystals arethen refluxed with a mixture of 200 ml. acetone and 25 ml. methanol, toyield, after standing at 25 to 29 C., 16.2 g.17u-hydroxy-16a-methylspiroxyane, M.P. 248254 C. decomposition, [121+126 (pyridine, c.=0.69). Paper chromatography shows only a single spotcorresponding to the slower moving component of the crude mixture.Recrystallization of a portion from methanol gives pure16a-methyl-17a-hydroxyspiroxyane, M.P. 246- 249 C. decomposition, [(11+131 (pyridine, c.=0.68); [0c] 10 (chloroform, c.=0.27);infrared:

112312 3420, 3280, 1740, 1685, 1620, 974, 766; .335 3420, 3200, 1723,1710, 1620, 970; ultraviolet: my 252 =7550 280 (6=1500) k min: 228(e=2950).

Analysis for C H N O Calc.: C73.58, H-8.03, N8.58 Found: C73.35, H-7.96,N8.48

The mercuric acetate test is negative.

The hydrochloride is prepared by treatment of a methanol suspension ofthe base with a slight excess of methanolic hydrogen chloride and thecrude product is precipitated by the addition of anhydrous ether.Recrystallization from isopropyl alcohol gives material which sinters at225, slowly decomposes and then melts with decomposition at 273-285 C.;+10 (water, c.=0.06): ultraviolet:

Al g 25l252 (e =6950), 281284 (6 =1600) 7\ min.: 227 (e=26()0),275 (e:1400) Paper chromatography shows a single spot with the same mobility asthe base. The mercuric acetate test is negative.

Analysis for C H N O HCl C H OH:

Calc.: C65.30, H8.34, N6.62, Cl8.38 Found: C65.48, H8.41, N6.63, Cl-8.13

The mother liquor from the first refluxing with acetone is distilled todryness, the residue is dissolved in 500 ml. ether, the solutionfiltered to remove insoluble material, and the filtrate treated with aslight excess of methanolic HCl. The yellow gum thus obtained issolidified by trituration with ether and is dissolved in ml. methanol.The solution is heated to boiling, 300 ml. methyl ethyl ketone is added,and distillation at atmospheric pressure is carried out until crystalsstart to separate, and the resulting mixture is allowed to stand at roomtemperature. The combined first three crops of slightly off whitecrystals weighed 9.5 g., M.P. 288296 C. decomposition, [(11 +102(pyridine, c.=0.68), +71 (water, c.=0.62). Recrystallization by the sameprocedure gives 7 g. white crystals, M.P. 300302 C. decomposition, [(21+86 (pyridine, c.=0.5), [121 +65 (Water, c.-=0.68). Paper chromatographyshows only a single spot corresponding to the faster moving compo- A3400, 3100, 1700, 1618, 759; ultraviolet: REX 1 23276 =7125 282283 (6=1450 Amin; 227 (75:3000), 275 (:1300). acetate test is positive.

Analysis for Cz HggNzOg'HCIZ Calc.: C66.19, H-7.50, N7.72, Cl9.77 Found:C66.09, H7.32, N8.00, Cl9.96

EXAMPLE 3 7-chl0roy0him bane To a suspension (protected from light) of56 g. (0.2 mole) yohimbane in 960 ml. methylene chloride containing 37ml. triethylamine is added, dropwise with stirring at 20 C., 72 ml. 50%(v./v.) solution of tert-butyl hypochlorite in carbon tetrachloridepreviously diluted with an equal volume of methylene chloride over aperiod of 45 minutes. After stirring an additional 45 minutes, themixture is stirred with 200 ml. water, dried over sodium sulfate, anddistilled in vacuo to dryness. The residue is triturated with 200 ml.absolute ethanol until a White crystalline solid is obtained. This iscollected and washed by stirring at room temperature for minutes with100 ml. more ethanol. The solid is dissolved in 2 liters of petroleumether, the solution is filtered to remove a small amount of darkinsoluble material, and is then evaporated to dryness to yield afterdrying in vacuo at 40 C. for four hours 38 g. of 7-chloroyohimbane, M.P.256270 C. decomposition, [a] D +27 (methylene chloride (c.=.54).

15,32? 225 (e=2l,200), 285-295 (6 =2400), )1 min. 246 (e =1800). 212;?1592, 778, 772, 754, 746 Analysis for C H N Cl:

Calc.: C72.48, H7.36, N8.90, Cl11.26 Found: C72.17, H-7.37, N-8.78,Cl11.30

EXAMPLE 4 Spiroxyane and 3-epispiroxyane A mixture of 9.5 g. ofcrystalline 7-chloroyohimbane, 125 ml. methanol, 100 ml. Water and 0.5ml. glacial acetic acid is refluxed forty minutes. The methanol isdistilled 01f and 150 ml. water is added. The solution is filtered toremove small amounts of insolubles, is basified by the addition of 10ml. concentrated ammonium hydroxide, and is extracted with methylenechloride. The dried methylene chloride solution is distilled in vacuo todryness and the residue is refluxed for a few minutes with acetonitrileto cause crystallization. After standing overnight there is collected6.8 g. of crystalline material whose paper chromatogram show spots Rf0.55 and 0.71.

A solution of 5 g. of this material in 1000 ml. boiling absolute etheris filtered, distilled at atmospheric pressure to a volume of 300 ml.,allowed to stand for to 24 hours at 22 to 27 C., and the resultingcrystals collected. There is obtained 1.4 g. of material, [a] -=-2(pyridine, c.=0.65), [oz] =42 (methanol, c.=0.71), Whose chromatogramconsists almost entirely of the slowest moving spot with only a trace ofthe faster spot. Recrystallization from acetonitrile gives 0.75 g.chromatographically pure spiroxyane, M.P. 189192 C. decomposition, [a]=3 (pyridine, c.=0.70), [a] =44 (methanol, 0:065), [a] =39 (0.1 N HCl,c.=0.70). x5353? 251-252 (e=7350), shoulder 283 (e =1650), a min. 226227(6 =2850). v 3400, 1728, 1710, 1621,

It gives a negative mercuric acetate test.

Analysis.Found: C77.13, H8.21, N9.23.

The ether filtrate is evaporated to dryness and is chroma- The mercurictographed over florisil using 50-50 benzene-chloroform as the eluant.The first 1000 ml. of eluate is collected and evaporated to dryness togive 2.2 g. of material [a] =58 (pyridine, c.=0.74), [a] =-26 (methanol,c.=0.68), whose chromatogram shows only the faster spot.Recrystallization from 'acetonitrile gives 1.5 g. 3-epispiroxyane, M.P.199-202 C. decomposition, [a] =6O (pyridine, c.=0.55), [a] =3O(methanol, c.=0.70), [u] =+l2 (0.1 N CH1, c.=0.58)

)rfiffi 251-252 (6:7000), shoulder 282 (=1500), A min. 227 (e =3000). 113230, 1710, 1678, 1617, 758,

744, 717 (broad); 3420, 3180, 1720, 1706, 1618, 0m.

11 max.

It gives a positive mercuric acetate test.

Ana1ysis.-Found: C77.20, H8.35, N--9.31.

EXAMPLE 5 7-clzl0ro-1 7 -h ydroxy-l 8-benzylideneyohimbane To a stirredsuspension (protected from light) of 30.7 g.18-benzylidene-17-hydroxy-yohimbane in 385 ml. methylene chloridecontaining 15 ml. triethylamine is added dropwise at 20 C., 29 ml. 50%(v./v.) solution of tert-butyl hypochlorite in carbon tetrachloride overa period of 15 minutes. After stirring an additional 30 minutes ml.water are added and the layers are then separated, and the organic layeris Washed with 100 ml. water. The organic layer is dried over sodiumsulfate and the solvent is distilled off to obtain crystalline 7-chloro-17-hydroxy-1S-benzylideneyohimbane, M.P. 188-191 C. decomposition, [oc]-,=-236 (pyridine, c.-= 0.65), [a] =200 (methylene chloride, c.=0.50),weighed 10 g. A sample on recrystallization from methylene chloridestarts to darken at 141 C. and melts with decomposition at 188191 C.

11 3360, 165 1, 1592, 784, 752, 705. Shoulder 252 Analysis for C H NOCl:

Calc.: C74.53, H-6.50, N-6.69, Cl-8.46 Found: C74.48, H-6.61, N6.79,Cl8.58

EXAMPLE 6 17-lzydroxy-J8-benzylidenespir0xyane and 17-hydro0cy-18-benzylidene-3-epispir0xyane from crystalline 7 -chl0ro 1 7-hydroxy-18-1)enzylideneyohimbane A mixture of 8.4 g.7-chloro-17-hydroxy-18-benzylideneyohimbane, 300 ml. methanol, ml.Water, and 0.5 ml. glacial acetic acid is refluxed 45 minutes. Themethanol is distilled off, 300 ml. more water is added, the mixture ismade basic by the addition of 10 ml. concentrated ammonium hydroxide,and is extracted with methylene chloride. The dried (sodium sulfate)methylene chloride solution is evaporated to dryness and the residue iscrystallized from acetone to yield 3.2 g. 17-hydroxy-18-benzylidenespiroxyane, M.P. 226 -229 C. decomposition, [a] :236(pyridine, c.=0.58), [0t]n=188 (chloroform, c.=0.64). Recrystallizationfrom acetone gives material M.P. 228230 C. decomposition,

[u] =l99 (chloroform, c.=0.5l) [a] =257 (pyridine, c.=0.60)

1 212 3540, 3220, 3040, 1718, 1690, 1650, 1617, 1590, 754, 745, 704,cum- MEI P 245 (e =21,000), inflection 280 (e :2250) A min.: 224(e=l1,700) 111p. acetate test.

It gives a negative mercuric Analysis:

Calc.: C-77.97, H-7.05, N7.00 Found: C78.13, H-7.31, N7.01

2231? 3440, 3360, 3200, 1708, 1688, 1652, 1618, 1598, 766 756, 750, 745,702 emf}. XZEZL 244 (e =20,500) )1 min. 224 (e=11,750).

It gives a positive mercuric acetate test.

Analysis:

Calc.: C77.97, H-7.05, N7.00 Found: C78.11, H7.29, N7.05

EXAMPLE 7 Preparation of mitraphylline and isomitraphylline fromajmalicine A mixture of 7 g. ajmalicine, 3 ml. triethylamine, and 120ml. methylene chloride is cooled to between 30 and 40 C. and a solutionof 4 ml. butyl hypoclrlorite in 12 ml. carbon tetrachloride is addeddropwise with stirring over a period of about 15 minutes, the materialsbeing protected from light. After stirring for an additional 15 minutesthe reaction mixture is stirred with 50 ml. water, the layers areseparated, and the organic layer washed with two more 50 ml. portions ofwater. The organic layer is dried over sodium sulfate and distilled invacuo to yield a dark oil which is dissolved in 100 ml. methanol. Afterthe addition of 100 ml. Water followed by 0.5 ml. glacial acetic acid,the resulting solution is refluxed 20 minutes. The methanol is distilledoff and 100 ml. more water is added. The small amount of dark insolublematerial is filtered off and discarded. The filtrate is made alkaline bythe addition of ammonium hydroxide and extracted with chloroform. Thedried chloroform solution is distilled in vacuo to dryness to give aresidue which solidifies on trituration with petroleum ether. Thebrownish yellow solid is triturated with 20 ml. methanol to yield 1.8 g.white crystalline material, M.P. 260263 C. decomposition, [a] =10(chloroform, c.:0.75). Recrystallization from methanol gives 1.5 g. ofmitraphylline, M.P. 265 266 C. decomposition, [a] =9 (chloroform, c.=0.94), [a] =+11 (pyridine, c.=0.65). The infrared spec trum issuperimposable in every detail with that of a sample of naturallyoccurring rnitraphylline.

The dark red filtrate from the methanol trituration is distilled invacuo to dryness. The residue is dissolved in 250 ml. ether, filtered toremove a small amount of insoluble material, and treated with an excessof an ethereal solution of picric acid. The resulting precipitate iscollected, washed with ether, and recrystallized from methanol to yield1.4 g. of material, M.P. 165 -188 C. decomposition. Two morerecrystallizations from methanol gives 420 mg. of isomitraphyllinepicrate, M.P. 207 209"'C.. 'cleco'mpositioii. Paper chromatography givesa single spot, Rf 0.85, as compared with mitraphylline which has Rf0.62. The infrared spectrum is superimposable with that ofisomitraphylline picrate prepared from natural sources.

Analysis for C H N O -;Calc.: C54.27, H4.56, -N 1l.72 Found: C54.54,H4.5'8, N111. 48

EXAMPLE 8 1 7u-acet0 xy-1 6ot-carb omethoxyspiroxyane A solution of 3 g.spiroxyane in a mixture of30 ml. dry pyridine and 15 ml. aceticanhydride is allowed to stand at 25 to29 C. for 30 hours. After theremoval of the solvent by distillation in vacuo, the residue is mixedwith 40 ml. Water, and 20 ml. aqueous ammonium hydroxide. The mixture isextracted with chloroform and the dried chloroform solution is distilledin vacuo to dryness to yield a residue which is recrystallized fromacetone to give 1.6 g. of 17o1-acetoxy-16a-carbomethoxyspiroxyane, M.P.22823l C. decomposition, [011 (pyridine, c.=0.78). Recrystallizationfrom acetone gives a M.P. 230233 C. decomposition, [01],; +73 (pyridine,c. :0.82); [011 -18 (chloroform, c.=0.63); infrared:

73:2 3200, 1730,1720, 1619,1168, 1228, 1246, 740 cmrg 3200,1730,1770,1700, 1618, 1248, 1160 cmr ultraviolet: my 251-252 (6 =7400 283shoulder e =1500) kmin. 227 (e=2800)m,u.

Analysis for C23H23N205:

Calc.: C66.97, H6.84, N-6.79 Found: C67.07, H6.69, N6.69

Since the base is too insoluble to carry out the mercuric acetate test,a small portion is converted to the hydrochloride by dissolving in etherand adding HCl. The precipitated hydrochloride which is filtered off andWashed with ether gives a negative mercuric acetate test. Paperchromatography gives a single spot Rf 0.45 relative tol6oc-carbomethoxy-l7a-hydroxyspiroxyane, Rf 0.16.

EXAMPLE 9 17-acetoxy-l-acetyl-16u-carbomethoxy-3-epispiroxyane A mixtureof 25 g. of 16u-carbomethoxy-17a-hydroxyspiroxyane and ml. acetic'anhydride is heated on a steam bath (temp. 9095) for 6 hours. It isallowed to stand 16-20 hours at 25 28 C. and then distilled in vacuo togive a syrup which is dissolved in 300 ml. of Water. The solution isbasified with ammonium hydroxide and the precipitated solid is filteredofi, washed with water, and dried over concentrated sulfuric acid in avacuum desiccator. The solid is refluxed with 2500 ml. Skellysolve C,and filtered While hot. The [filtrate is distilled to dryness and theresidue crystallized from 50 ml. acetonitrile to give 12.5 g. ofproduct, M.P. 191-193 C. decomposition, +79 (pyridine, c.=0.91).Recrystallization from acetonitrile gives M.P. 190-193 C. decomposition,[011 +77 (pyridine, c.=0.7); [01],; +43 (chloroform, c.=0.62); infrared:

use? 1758, 1732, 1693, 1020x 1004, 1200, 1176, 1016, 777, 7 10 0111722 958 1734, 1702, 1604, 1279, 1248, 1015; ultraviolet: 12:31 228-230 (6=9860), 209-271 (=1250) 1 min., 222-234 59540 ma.

Analysis for CZ5H3ONZOG:

Since the base is too insoluble to carry out the mercuric acetate test,a small portion is converted to the hydrochloride by dissolving in etherand adding I-ICl. The precipitated hydrochloride which is filtered offand washed with ether gives a positive mercuric acetate test. Paperchromatography gives a single spot, Rf 0.74 relative to L- acetoxy-l6a-carbomethoxyspiroxyane, Rf 0.45.

Concentration of the acetonitrile mother liquor to a volume of 20 ml.gives 4.5 g. of a second crop, M.P. 193 C. decomposition, [011 +80(pyridine, c.=0.63).

EXAMPLE 1O Z-desoxy-l 7 ot-hydroxy-l 6 a-methylspiroxyane A suspensionof 9.8 g. (0.03 mole) 17OL-hydI'OXy-160t' methylspiroxyane and 10 g.lithium aluminum hydride in 750 ml. dioxane is refluxed with stirringfor 12 hours.

The reaction mixture is hydrolyzed by the dropwise addition of in excessof the calculated amount of water, stirred with a mixture of 10 g.anhydrous sodium sulfate and 20 g. Supercel, and filtered. The residueis extracted by refluxing with two 250 ml. portions of tetrahydrofuranand filtering while hot. The combined dioxane and tetrahy-drofuranfiltrates are distilled to dryness, the residue is dissolved in 30 ml.isopropyl alcohol and ml. 6N methanolic hydrogen chloride is added.Addition of 150 ml. anhydrous ether followed by refrigeration gives 6.5g. of the reaction product 2-desoxy-l7e-hydroxy-l6a-methylspiroxyane,M.P. 288-295 C. decomposition, [011 =+40 (water, c.=0.65).Recrystallization from isopropyl alcohol gives the pure dihydrochloride,M.P. 290- 297 C. decomposition, [a] =+41 water, c.=0.6), [u] =+98 (90%aqueous pyridine, c.=0.6), [111 =+72 (methanol, c.=0.6).

Analysis for C H N O2HCl:

Calcu C-62.33, H-'7.85, N7.27, Cl18.40 Found: C62.05, H8.08, N7.07,Cl18.28

An aqueous solution of the 500 mg. dihydrochloride is hasified withammonium hydroxide and extracted with methylene chloride. The driedmethylene chloride solution is distilled to dryness and the residue isrecrystallized twice from acetone to give 280 mg. of the pure base, M.P.178-180 C., [a] =|l04 (pyridine, c.=0.61), [a] =1-42 (chloroform,c.=0.51). Infrared.

3620, 3320, 1612, 754, 748, 740, @55 3610 (20), 3416 so 1606.Ultraviolet: sea 243 (E=6750), 296 5:2900

x min: 723 6:3 :50 269 @1100 Analysis for C20H25N2O:

EXAMPLE 1 1 1 7lx-hydr0xy-1 6a-lzydroxymethyl-Z-desoxyspiroxyane Amixture of 5 g. of 160l-C3I'b3l16th0XY-17OL-hydIOXyspiroxyane and 5 g.lithium aluminum hydride in 300 ml. dioxane is refluxed for 6 hours,diluted with 1000 ml. dry tetrahydrofuran and allowed to stand 18 to 24hours at 25-29 C. The mixture is hydrolyzed by careful dropwise additionof a slight excess of water, stirred with anhydrous sodium sulfate, andfiltered. The solid residue is extracted by refluxing with two 300 ml.portions of chloroform and the combined chloroform and dioxanetetrahydrofuran solutions are distilled in vacuo to dryness. Since theresidue could not be solidified, it is dissolved in methanol, acidifiedby the addition of methanolic HCl and treated with ether. Initially,there is formed an oil; this solidifies on trituration with severalfresh portions of ether. The solid is recrystallized from methanol togive 3.2 g. of l7a-hydroxy-l 6u-hydroxymethylspiroxyane dihydrochlon'de,M.P. 275 285 C. decomposition, [011 +83 (95% aqueous pyridine, C.=0.80).Half of this is recrystallized once more from methanol to give 1.2 g. ofmaterial, M.P. 275 285 decomposition, [011 +86 (95% aqueous pyridine,c.=0.l83); {a]=+41 (water, c.=0.61); infrared spectrum:

Nuiol p 3520, 3440, 2640, 2620, 2400, 1600, 1572, 1022 778, 760 emf.

Analysis for C H N O .2HCl. /2 CH OH:

Calc.: C58.99, H-7.73, N6.7'1, Cl16.99

Found: C59.-0O, H7.7l, N7.0l, Cl16.52 The remainder of the oncerecrystallized dihydrochloride is dissolved in 25 ml. water, basified bythe addition of ammonium hydroxide, and the mixture is extracted withchloroform. The dried chloroform solution is distilled to dryness togive a residue which is recrystallized twice from acetone to give 900mg. 17a-l1YdIOXy-16oc-hY- droxymethylspiroxyane base, M.P. 215 219 C.de-

Nuiol max.

composition, [01],; +133 (pyridine, c.=l.00); infrared spectrum:

A min. 223 (e=3035), 269 (6 820) IIUA.

Analysi for C H N O Calc.: C73.14, H8.59, N8.53 Found: C72.85, H8.63,N8.32

EXAMPLE 12 1 7-keto-3-epz'spiroxyane A mixture of 37 g.16lx-carbomethoxy-17a-hydroxy spiroxyane and 1500 ml. xylene isdistilled at atmospheric pressure until about 500 ml. of distillate iscollected, 750 ml. of cyclohexanone previously dried over sodium sulfateand g. aluminum phenoxide are successively added, and the mixture isrefluxed with stirring for 40 hours. After standing at room temperature,the mixture is extracted with five 400 ml. portions of 10% HCl and thecombined aqueous layers are washed with either. The aqueous solution isbasified with aqueous ammonium hydroxide solution, and extracted withfour 250 ml. portions of chloroform. The dried chloroform solution isdistilled to dryness to give a residue which is crystallized fromacetone to give 9.5 g. of the reaction product 17- keto-3-epispiroxyane,M.P. 228230 C. decomposition, [m] =-{53 (pyridine, c.=1.1).Recrystallization from acetone gives a material, M.P. 228 230 C.decomposition, [a] =-l55 (pyridine, c.=l.0); infrared spectrum: 1133i?3300, 1726, 1690, 1624, 756, 742, cmfi ultraviolet: AZfZ 251252(e=6820,) 282 shoulder (e=1800) )1 min. 228 (e=3720) mg. The compoundgives a positive mercuric acetate test and moves as one spot, Rf 0.46 onpaper chromatography.

Analysis for C H N O Calc.: C73.52, H7.15, N-9.03 Found: C73.23, H-7.26,N-9.21

EXAMPLE 13 18-benZylidene-1 7-keto-3-epispiroxyane A solution of 1 g.3-epispiroxyane, 1 ml. benzaldehydc, and 0.5 ml. 10% aqueous sodiumhydroxide in 50 ml. methanol is refluxed for 16 hours. After theaddition of 2 ml. more benzaldehyde and 0.5 ml. 10% sodium hydroxide,the refluxing is continued for eight hours longer. The solvent isremoved by distillation in vacuo and the resulting oil is-dissolved indiluted acetic acid, the solution is basified by the addition ofammonium hydroxide, and the mixture is extracted with chloroform. Thechloroform solution is charcoaled, dried over sodium sulfate, anddistilled in vacuo to dryness. The residue is dissolved in absoluteether, a slight excess of methanolic hydrogen chloride is added, and thecrude hydrochloride is filtered off and washed with ether. It isrefluxed with 300 ml. acetone filtered off, and dissolved in water. Theaqueous solution is basified with ammonium hydroxide, the resultingprecipitate is filtered oil, washed with Water, dried and recrystallizedfrom methanol to give 0.55 g. of 18-benzylidene-l7-keto-3-epispiroxyane,M.P. 238241 C. decomposition, [a] =25 (pyridine c.=0.50)

11:12 3240, 1790, 1684, 1618, 1592, 755, its? shoulder 230 (e=10,000),265 ($13,000 292 (6=17,500)

Amin. 236 (e=8000), 268 (e-12,500). Analysis for C H N O Calc.: C-78.36,H6.58, N-7.03 Found: C78.20, H-6.54, N7.23

EXAMPLE 14 I 7-Hydr0xy-18-benzylidene-S-epispiroxyane from81-benzyll'a'ene-1 7 -ket0-3 -epispz'roxya'ne A mixture of 1 g.IS-benzylidene-l7-keto-3-epispiroxyane, 1g. potassium borohydride, and25 ml. methanol was stirred at room temperature for 3 hours and then 75ml. water is added. The resulting white precipitate i filtered off,washed with water, dried, and recrystallized from methanol to give *03g. of product, M.P. 151-155 C. decomposition, 315 (pyridine, c.=0.63) [M225 (chloroform, c.=0.56).

Analysis for C26H26N202:

Calc.: C77.97, H7.05, N7.00 Found: C--77.93, H6.89, N-7.29

EXAMPLE 15 1 7 -hydroxy-3-epispir0xyane A solution of 2 g.17-keto-3-epispiroxyane in 100 ml. methanol is stirred with 2 g.potassium borohydride at room temperature for 24 hours. The methanol isdistilled off in vacuo, 50 ml. water is added and the mixture isextracted with chloroform. The chloroform is dried :over sodium sulfateand distilled in vacuo to dryness to give -l7 hydroxy 3 epispiroxyane[a]-=+35 (pyridine, c. =O.75) which is recrystallized from acetone to give1.4 g. of product, M.P. 235 242 C. decomposition, [a] =+52 (pyridine,c.=1.25). Further recrystallization gives a M.P. 238245 C.decomposition, [a] =+57 (pyridine, c.=l.l2) infrared spectrum:

$311 34.40, 3180, 1711, 1692,1619,752,ultravioletspectrum: AZFZPOH 251(e =7180), 282 (e =180O) min. 228 (-e=3900).

Analysis for C H N O Calc.: C73.05, H7.74, N8.97 Found: C-72.95, H7.70,N8. 87

wherein R is a member of the group consisting of hydrogen,

OCH;

and lower alkyl, R is a member of the group consisting of hydrogen,keto, hydroxy, lower alkoxy and acyloxy, R is a member of the groupconsisting of hydrogen and =CHC H R in which R, is a member of the groupconsisting of hydrogen, halogen, hydroxy and -OCH and R is a member ofthe group consisting of hydrogen and and the nontoxic pharmaceuticallyacceptable acid addition salts thereof.

2. Spiroxyane.

3. 3-epispiroxyane.

4. 16a-methyl-l7a-hydroxyspiroxyane.

1 6a-methyl-17a-hydroxy-3-epispiroxyane. 16a-carbomethoxy-17a-hydroxyspiroxyane.16a-carbomethoxy-17a-hydroxy-3-epispiroxyane.18-benzylidene-17-hydroxyspiroxyane.18-benzylidene-17-hydroxy-3-epispiroxyane.

10. l7-acetoxy-l-acetyl-l6u-carbomethoxy spiroxyane.

11. 17 acetoxy l-acetyl-16a-carbomethoxy-3-epispiroxyane.

12. 17-ketospiroxyane.

13. 17-keto-3-epispiroxyane.

14. 1Goa-methyl-l7a-hydroxy-Z-desoxyspiroxyane.

15. 1 6a-methyl-17-hydroxy-2-desoxy-3-epispir0xyane.

16. 16oz hydroxymethyl 171x hydroxy 2-desoxyspiroxyane.

17. hydr-oxymethyl 17a-hydroxy-2-desoxy-3-epispiroxyane.

18. 17x-acetoxy-16m-carbomethoxy spiroxyane.

19. 17a-acetoxy-16a-carbomethoxy-3-epispiroxyane.

20. A process for the production of a compound of the formula:

N I i which comprises hydrolyzing. at an acidic pH 21 compound of theformula:

R1 Ra wherein R is a member of the group consisting of hydrogen OCHa andmethyl, R is a member of the group consisting of hydrogen, oxygen,hydroxy, lower alkoxy and acyloxy, R is a member of the group consistingof hydrogen and =CHC H R in which R, is a member of the group consistingof hydrogen, halogen, hydroxy, and OCH and R is a member of the groupconsisting of hydrogen and 21. A process for the production of acompound of the formula:

of the formula:

which comprises heating a compound of the formula:

GHaO-- H with cyclohexanone and aluminum phenoxide in an inert organicsolvent.

23. A process in accordance with claim 22 wherein said inert organicsolvent is xylene.

References Cited by the Examiner UNITED STATES PATENTS 8/ 1955 Pfisteret al 260285 6/ 1964 Shavel et a1 260-240 OTHER REFERENCES Ban et al.:Chemistry and Industry, 1960, page 349 (Mar. 26, 1960).

Gaylord: Reduction with Complex Metal Hydrides, pages 100 to 102,Interscience Publishers, Inc. (N.Y.) (1956).

Godtfredsen et a1.: Acta Chem. Scan, vol. 10, pages 1414-1421 (1956).

Hendrickson: I. Am. Chem. Soc., vol. 84, pages 643- 653 (Feb. 20, 1962).

Manske: The Alkaloids, vol. 7, pages 19-2'0, 62, 86, 88 and 90-91,Academic Press (N.Y.) 1960.

Shavel et 211.: II, I. Am. Chem. Soc., vol. 84, pages 11320- 1321 (April1962).

IRVING MARCUS, Primary Examiner.

JOHN D. RANDOLPH, WALTER A. MODANCE,

Examiners.

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF THOSE HAVING THEFORMULAS
 20. A PROCESS FOR THE PRODUCTION OF A COMPOUND OF THE FORMULA: